1/ we don't knwo your version(s), it is hard to tell if something is new in a version we don't know compare to a version we don't
2/ Copy and paste what you execute and get (SQL*Plus session)
3/ Before, Please read OraFAQ Forum Guide and How to use [code] tags and make your code easier to read.
Make sure that lines of code do not exceed 80 characters when you format.
Indent the code, use code tags and align the columns in result.Use the "Preview Message" button to verify.